I 
38 FALSIFICATION OF WINE VINEGAR, &C. 
date. Lamarre in his Traite de la Police, says that vinegar 
makers add to their vinegar, red pepper in order to render it 
more pungent. 
Some manufacturers introduce into the confection of vine- 
gar, long pepper, pyrethrum, grains of paradise, mustard seed, 
and other acrid vegetable substances. The methods of detect- 
ing the presence of these substances, is to evaporate at a low 
heat this vinegar until it attains the consistence of an extract, then 
to examine the residuum, which has an acrid biting and even 
caustic taste, when these substances have been added. 
Vinegar thus medicated, if tasted carefully can readily be re- 
cognised. In effect, it leaves upon the palate and in the throat 
an acrid, then burning sensation. 
Means of detecting the presence of copper and lead in 
vinegar. 
The presence of these mineral products, cannot be consi- 
dered as a falsification, but as the result of negligence in the 
fabrication, or rather of the unfitness or of the bad choice of 
the utensils which have been employed for keeping the vine- 
gar. The presence of these mineral preparations can be 
readily determined, 1. by sulphuretted hydrogen, which im- 
parts a brown colour to the liquid and indicates the presence 
of lead and even copper; 2. by ammonia, which occasions a 
blue colour when the vinegar contains a salt of copper; 3. by 
the ferrocyanate of potassa, which occasions a grumous pre- 
cipitate when a salt of copper is present; 4. by the chromate 
of potassa, which affords a yellow precipitate when a salt of 
lead may exist in the vinegar. But in order to render the ef- 
fect of the reaction more sensible, it is better, when these salts 
are sought for in vinegar, to evaporate it to three-fourths and 
to experiment only upon the remainder, which will contain 
them in a less dilute state. 
Of the modes of appreciating the strength of vinegars. 
Many methods have been proposed to determine the 
strength of vinegar, that is to say, its degree of acidity. 
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